                 {}
                 {'ui/query (fn [] "Hello world")})
       (is (= "Hello world" (text (sel1 "#result")))))
+    (testing "to callback binding to global cells"
+      (install! {:text "Hello world"}
+                "{:upcased-text #= (ui/upcase #= :text)}"
+                "[:div#result #= :upcased-text]"
+                {}
+                {'ui/upcase (fn [_ text]
+                              (str/upper-case text))})
+      (is (= "HELLO WORLD" (text (sel1 "#result")))))
     (testing "to callback binding to data"
       (install! {:text "Hello world"}
                 "{:upcased-text #= (ui/upcase #= :text)}"

        (async done
          (go (is (= "Hello" @received-value))
              (done)))))
    (testing "Invocation with deep binding"
      (install! {} "{:user {:name \"John\"} :text \"Hello world\"}"
                "[:div
                 [:button {:id \"btn\" :on-click (ui/handle-click #= [:user :name] #= [:text])}]

        (async done
          (go (is @clicked)
              (done)))))
    (testing "invoked with value arguments"
      (let [received-value (atom false)]
        (install! {} "{:text \"Hello\"}"
                  "[:div
